Xerox 5090 Family- Good Vibrations

By Raymond Cote

For starters, I would like to thank all the techs in the field and the print shops that have contributed their suggestions and repairs for various ailments in the Docutech and 5090 families of copiers.  It’s always good to know that you are actually reaching someone out there and issues are being resolved.  I am also greatly appreciative to ENX Magazine for allowing me to write this column on maintenance practices.  In all reality, it has helped me more significantly because I have learned a few new tricks and discovered a few things as well. There were so many problems that only happened once or twice in the course of my career and when they were fixed we quickly forgot the fix. So if the problem came back again in a year or two, we would have to troubleshoot all over again from scratch.

When I was going to college, one of my professors repeatedly said that you really never know a machine or a device until you try to write a report on its repair and maintenance.  And I found out he was absolutely right about that.  I attended the Xerox 5090 school in May 1988 and have been repairing that family of copiers ever since. You would think that after 17 years on the product you would have seen everything there is to see. Well, guess again, Virginia—there is never a month that goes by where something doesn’t fall out of bed that defies all logic. The fleet is aging and new problems are arising every day. Meanwhile, Xerox has introduced a new family of copiers to replace this aging fleet, knowing full well they have served the industry well. I think it is their way of saying, “let’s move along.”  It’s just a matter of time before the only people that are servicing the 5090 family are Independent Service Organizations and self-maintainers.

When I was employed by the manufacturer, it was not too unusual to see 25, 30, or even 50 million copies on the hard meter, and as the copier aged the number would always increase until Xerox replaced the machine. Sometimes you even ran across a copier that had almost 100 million copies on the hard meter.  Today, I have personally seen hard meters on the Xerox 4135 printer that have recorded over 200 million copies. That’s a lot of copies, and along with the high volume and the longevity comes a new phenomenon—and its by-product is totally unrelated system faults and random shutdowns.  It is extremely frustrating to troubleshoot a system fault that changes constantly to something new.  And when the problem “just goes away” all by itself, you are totally lost. That’s when you start cussing up a storm in a foreign language. It certainly doesn’t help the situation, but it does make you feel a whole lot better.

     Over the past 18 months I have been discovering that the fretting of pins in certain plug/jacks is the cause of most of these random system faults. It would be in your best interest to examine these plugs and jacks and repair them at your earliest conveyance. There is also another point of interest to consider:  fire.  Yes, I did say fire, like in burn. Think about this:  When a (male) pin starts to vibrate inside a (female) socket, fretting will occur. The fretting will be the results of vibrations, and arcing will cause heat to build up as well. When it gets hot enough there will be spontaneous combustion and then a meltdown, if you’re lucky. If not, then it will be a fire that only a CO2 fire extinguisher can put out. By that time it will have been too late and the damage in most situations is usually beyond repair.

     There are several areas of interest to examine in the 5090 family:

—The AC Distribution Panel at the rear of the copier: Check Plug/Jack Location Drawings (figure 17 in the manual and PL 5-A11 on the microfiche) to locate the panel. Turn off the copier and remove the 50-amp plug from the wall as well. If you have the configuration where there are multiple power cords, remove them all; this will probably reduce the shock effect.  Remove the right rear panel on the processor and turn the two quarter-turn Dzus fasteners to open the AC Distribution Panel.

 For starters let’s check the plastic relays for pitted contacts. They can be viewed though the clear plastic covers. If you see any burned or pitted contacts this would be a great time to replace them. Relay K106, Binder Relay, Relay K102, Interlock Relay, and Relay K403, Print Power Relay. In the 5090, these relays are 109P397. Check the Fiche for the correct locations and never substitute any foreign relays for the ones the book calls for.  Check the other two large relays as well for burned or pitted contacts:  Relay K402 (part number 109E241), Main drive run, and Relay K105 (part number 109E262 LVPS). The last two black relays must be partially taken apart to examine the contacts. If you are satisfied that all the contacts are in good condition, continue with the inspection; otherwise, replace all the relays that show signs of pitting, corrosion or arcing.

The next area of interest is the plugs/jacks on the AC Distribution Panel. Cut the ty-wraps on P4211/P3 (left side of the AC panel) and disconnect the plug/jack. Examine all the pins and make sure there is no fretting or any damage to the plug /jack connector. Do the same thing to the J377/P2 connector, and again to the P269/J1 connector.  Usually this connector will show some signs of fretting or pitting of some of the pins. I have personally observed that many have had bad pins in them.

     If you are still wondering what causes fretting and arcing (of the pins), you can be assured it isn’t smooth sailing. The culprit is normal vibrations when the copier is in the print cycle and making copies.  After repairing the burned and pitted pins on the AC Distribution Panel, reconnect the plug/jacks and secure them with 6” ty-wraps to reduce the vibrations.   The ty-wraps will not prevent fretting and pitting of the pins, but it will certainly slow down the process.

—The second area of concern is the Low Voltage Power Supply (LVPS) located at PL5-B13.  Check both relays for pitted contacts: K104 24-volt Interlock Relay and K 103 34-volt Interlock Relay (part number 109P397). Then check all the plug/jacks to the LVPS, especially the 24-volt DC plug/jacks. Make sure all the pins are free of any contamination from rust, pitting or fretting. Pay particular attention to P215 / J215 and P315 / J315.

—The next area of concern is the plugs and jacks on the Illumination Power supply. Over the years I have replaced many pins in the plugs /jacks that get attached to the Illumination Power Supply. Examine the following plugs and jacks: J257 / Js, P216 / J4, J258 / J2, P267 / J1, all located on the rear of the Illumination Power supply. I think one of the giveaways that there may be a problem with a connector is an abundant (random) amount of 06-xxx shutdowns. Check the male pins to see if you can find several burned or pitted pins. Replace them as soon as you can because they could be a fire hazard.

—The next area of concern is the plug/jacks directly over and near the MIM compressor. There have been numerous fires reported that were caused by fretting or burned and pitted pins in plug/jacks J268 /P1 and P10 / J2. Vibrations also have been blamed for chaffing the wire nets in and around the MIM compressor assembly (PL3-E5) and shorting to ground. On your next visit, remove the left rear panel and (after unplugging the copier!) examine the wires near the MIM compressor assembly. Make sure that no wires are damaged or starting to chafe from vibrations.  Keep in mind that if you ever have a fire in this area it will be almost impossible to repair the damage, even if it’s slight. The wire harness is not spared by Xerox, and to remove one from another copier would be useless because the harness may not be the same. As my dad used to say, “An ounce of prevention is worth a pound of cure.”

     This article was written because a technician took the time to call me and ask for assistance in troubleshooting a 06-xxx system fault that didn’t want to go away.  And after replacing every component in the circuit he was still in the same place—lost. After close and careful examination of the plugs/jacks on the rear of the Illumination Power Supply, he discovered two pitted pins that caused the problem. Unfortunately, you can’t ty-wrap those plugs/jacks because there is no place to ty-wrap them to—the only way to keep on top of this is to make regular examinations of those plugs/jacks.

Another technician informed me about a fire caused by chafing wires in and around the MIM compressor assembly.  At first he was determined to repair the burned wires and the damaged plug / jacks, but after two weeks of working on the machine (about 85 hours) he gave up and replaced the copier.

All technicians are encouraged to submit ideas or remedies for repair on any Xerox 5090 family or Docutech family copiers / printers. Information will be passed on to the field, possibly helping you out of a jam in the near future.

If you have information that you would like to share with the field, please feel free to submit your ideas to VillageCopierNY@aol.com and I will place your suggestion or fix in the next issue of ENX. From what I hear in the field, it seems that many ex-Xerox technicians miss the field engineering team in Rochester, N.Y. Somehow it was always reassuring to hear a voice on the other end of the phone and a field engineer making a suggestion for a fix on your problem